'buttonDeleteDomainConfirmationDescription' => 'buttonDeleteDomainConfirmationDescription' => 'Removing this website will also delete all related files, directories, and web applications from the server.',

to

'buttonDeleteDomainConfirmationDescription' => 'Removing this website will also delete all related subdomains, files, directories, and web applications from the server.',

NOTE: Replace path
/usr/local/psa/admin/application/smb/resources/languages/en-US/
with current used locale, for example, if German locale is in use correct path will be
/usr/local/psa/admin/application/smb/resources/languages/de-DE